I'm planning to build a new heating system for next year that burns wood and waste oil.

1.What is the advantages of an outdoor boiler vs an indoor hot air system?

2. Has anyone used oil instead of water in a boiler?
I know we use heated oil in plastic injection molding to get to temps over
200 deg. F.
My thoughts on this is that oil won't freeze if unit isn't running.
Oil won't rust out the unit.

3. I'm thinking of having two different fire boxes, wood on one end
and wasteoil on the other end vs one all the way thru the unit.
My thought on this is I can make the fire boxes replaceable if seperate or
removeable for repair if they would ever start to leak.

4. Is it best to insulate the boiler if it has a building around it that is insulated.

I would like imput from anyone that has info on this.
Thanks
Bret Green

I have been using an outdoor wood boiler since 2006 and I really like it. One big advantage of this is that all the mess from the wood and smoke stays out of your house. I have found that the type of wood really doesn't matter much. Anything will burn in it. I do realize that hardwoods yield more BTU's than pine, however, it is nice to be able to go through the woods and clean up any kind of dead or blow downs and make use of them. Another advantage is that I can heat multiple buildings with one unit. I currently heat a 1858 Brick house (3 stories) and a new garage (26 x 40 and 2 stories). I burn about 35 cords of wood per year. I will say that if you don't have a lot of time to cut, split and stack the wood, then a boiler is probably not your best option. Also, if you want to leave for a few days in the winter you need to have someone come and keep the fire going.As to the rest of your post, I do not have any knowledge. Sounds like a fun and interesting endeavor though.Good luck with it and let us know how it turns out.